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Re: pruning the semantics document (and "meaningless terms")

From: pat hayes <phayes@ai.uwf.edu>
Date: Wed, 11 Dec 2002 16:00:30 -0600
Message-Id: <p05111b0dba1d6488fe85@[10.0.100.86]>
To: Frank Manola <fmanola@mitre.org>
Cc: w3c-rdfcore-wg@w3.org

>Pat--
>
>I'm sorry, but on the basis of Patrick's recently-expressed concerns 
>about "meaningless terms", I've got to temporarily object to this. 
>The problem is roughly this:
>
>When I said:
>>>All these terms are discussed in the Primer (in some cases extensively),
>>>together with examples of their use.  In all the use cases, there are
>>>caveats expressed that describe these as "intended meanings",
>>>
>Patrick said:
>>
>>  But intended by whom? If they are intended by the RDF Core WG, then
>>  they should be normative. If they are intended by someone else, why
>>  should we say anything about them or even include the terms in the
>>  RDF vocabulary.
>
>and later said:
>>  Precisely. I think that the Primer should reflect, in minimally technical
>>  and accessible terms the normative content of the other documents, and
>>  the examples and verbage for these terms does in fact suggest that RDF
>>  is asserting meaning for these terms which it is not.
>
>So it seems to me that when the Semantics document describes the 
>intended meaning of terms from this vocabulary, like containers and 
>collections (and reification, and ...), it's a normative statement 
>of our intent (even if we can't fully define the semantics 
>formally), and it's OK then to elaborate on that in the Primer.

Well, OK, not a big deal. I guess I was just worried that what you 
say in the Primer about collections/containers/reification is pretty 
much *exactly the same* as what I say in the MT doc, in some cases in 
almost the same words and with the same examples. So it just seems 
like duplication, is all I meant; and since the MT is, arguably, kind 
of overloaded with expanatory prose in any case (for an MT doc, that 
is), why not do some redundancy-pruning?. I wasnt meaning to get 
involved with normative/informative issues particularly. About half 
the semantics doc is explicitly labelled as non-normative in any case.

>[NB:  The Semantics document I'm referring to is 
>http://www.coginst.uwf.edu/~phayes/RDF_Semantics_finalCall.html]
>
>If anyone thinks the above is a sneaky argument, consider also the following:
>
>a.  Several applications described in Section 6 of the Primer use 
>the container vocabulary, and it seems to me they use it correctly. 
>Although we can't formally define everything about this vocabulary, 
>it seems to me we've stated it well enough in English so people can 
>use it with a reasonable degree of interoperability.  We could 
>elaborate more on that in the Semantics document (describing it as 
>"intended" again) if people insist on something normative.  But I 
>don't understand how directing people away from that vocabulary, and 
>forcing them to individually invent N different representations for 
>containers on their own, helps achieve the goals of 
>globally-consistent meaning.
>
>b.  We added the "meaningless" collection vocabulary not that long 
>ago.  This isn't a piece of bad old legacy syntax from M&S.  Did we 
>really have no normatively-describable intent in doing that?

No, and I had a perfectly fine formal MT for it, but the WG decided 
that we shouldnt use it. I still am puzzled about this decision, 
which was apparently taken on the grounds of 'RDF style'. Hey ho.

>If so, then we can delete it now without impacing anyone can't we? 
>If we actually mean something by it (and I think we did), then let's 
>say it.  (And I think the Semantics document *does* say it, and the 
>Primer reflects that).
>
>c.  There are some problematic aspects of the other vocabulary 
>items, but not that many really.  rdfs:comment?  Say in some 
>normative document that it's intended to provide a place to put 
>comments (actually, I think Schema covers that, at least about our 
>"intent", and also does so for the other terms mentioned in the 
>following).  No one expects any more formal semantics than that for 
>a comment anyway do they, and why not have a pre-defined way to make 
>comments (most languages do)? rdfs:label?  Same comment. 
>rdfs:seeAlso?  Relatively harmless.  It says there'a relationship 
>between the subject and object of the statement. Big deal.  That's 
>exactly what the formal semantics are.  Users could define their own 
>names for that relationship depending on how they use it, so we 
>could delete it, but why bother.  rdfs:isDefinedBy?  It's a 
>subproperty of rdfs:seeAlso.  Say what the intent is (which the 
>Schema document does) and forget it.  rdf:value?  We've been working 
>on that, but I don't think we've achieved closure yet.  (But there's 
>a nice description of our intent in the Semantics document.)
>
>So my current suggestion is to leave the current descriptions in the 
>Semantics document, so they're "normative", and we can continue to 
>talk about the uses of useful vocabulary in the Primer (of course, 
>with appropriate caveats about what is *not* guaranteed about uses 
>of these terms).
>
>--Frank
>
>pat hayes wrote:
>
>>
>>After reading through the Primer, particularly section 4, I propose 
>>that almost all of section 3 of the semantics document be simply 
>>removed. It's all in the primer section 4.
>>
>>Semantics section 3 should just list the RDF vocabulary that isn't 
>>being given a formal meaning, say explicitly that it isn't, and 
>>refer to the Primer for the informal meaning. If anyone feels that 
>>there are any subtleties in section 3 that aren't in the primer 
>>text as it stands, then lets put them into it. I don't think there 
>>are many, if any, in fact.
>>
>>Anyone object? Frank??
>>
>>Pat
>
>
>--
>Frank Manola                   The MITRE Corporation
>202 Burlington Road, MS A345   Bedford, MA 01730-1420
>mailto:fmanola@mitre.org       voice: 781-271-8147   FAX: 781-271-875


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Received on Wednesday, 11 December 2002 17:00:35 EST

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